04 Prohlein,s of Econonilc Biolofjn ^'* E(ist Africa 



insecticide the great majority of insects fly into the air and hover over 

 the trees in a cloud. They cannot, however, stand heavy rains, and shortly 

 after these commence the pest disappears. The insect appears in very 

 large numbers only in a prolonged dry season and then reigns supreme 

 until the next rains clear it ofi" again. Where it originally came from, its 

 life-history, and what becomes of it during the rains, are problems still 

 awaiting solution. 



A third pest, which is often responsible for a large amount of re- 

 ))lanting, is the cut- worm, a larva of various species of the moths 

 Agrulis and Euxoa. E. segetum is the most common. Newly planted 

 out seedlings are very subject to attack and are girdled just below 

 ground level. Gathering by hand, and the protection of the young 

 stem by a band of some durable substance soaked in grease, are the 

 methods employed in controlling this pest. Baits of chopped grass 

 sprinkled with Paris Green have not proved very efTective. 



The remarks relating to the sound cultivation of the cocoanut palm 

 are equally applicable to coffee and indeed to any permanent crop. 



Finally, as regards coffee, it is a point of considerable interest to 

 compare the yield of the East African crop with that of other countries 

 of the East. In the best days of Ceylon coffee the heaviest yield was not 

 more than | ton to the acre, and the average was rather below this. 

 In East Africa the average yield is greater; over a ton has been recorded 

 more than once, and f ton to the acre is not considered an excessively 

 heavy crop. Latterly, however, it has been found by experience that 

 the trees do better, are not so exhausted and are therefore more capable 

 of withstanding disease, if the crop is limited to not more than \ ton to 

 the acre. This can be done by stripping off some of the young fruits soon 

 after they have set. 



V. The Forests of the Highlands. 



The forest areas of East Africa are not very numerous but are of 

 considerable extent, the most important for valuable timber being those 

 of the Highlands at altitudes ranging from 6000 to 8000 feet. Of the 

 many different trees which yield good timber only a few are used at 

 present to any great extent. The yellow wood, Podocarpus gmcilior, and 

 the so-called East African Cedar, Juniperus procera, are used extensively 

 in building. The ni'hugu, Brachylaena hutchinsi, a giant member of the 

 Compositae, is largely used for fuel, and for fencing and telegraph poles 

 as white ants do not attack its wood. 



